Barney Thomson—an awkward, diffident, Glasgow barber—lives a life of desperate mediocrity. Shunned at work and at home, unable to break out of a 20-year rut, each dull day blends seamlessly into the next. However, there is no life so tedious that it cannot be spiced up by inadvertent murder, a deranged psychopath, and a freezer full of neatly packaged meat. Barney Thomson’s  uninteresting life is about to go from 0 to 60 in five seconds, as he enters the grotesque and comically absurd world of the serial killer.